Page 73 - 新思维科学学生用书7 样章

2 Materials and their structure

2.8 a Give the symbol for each element.

i magnesium [1]
ii oxygen [1]
iii hydrogen [1]
iv calcium [1]

v boron [1]
b Name the element with the given symbol.
i C [1]
ii Na [1]

iii K [1]
iv Cl [1]
v Si [1]
c Explain why scientists use symbols for the elements. [1]

d Explain why some symbols, such as Cl and Si, have two letters. [1]

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